The present invention relates to an improved mapping catheter that is particularly useful for mapping electrical activity in a tubular region of or near the heart.
Atrial fibrillation is a common sustained cardiac arrhythmia and a major cause of stroke. This condition is perpetuated by reentrant wavelets propagating in an abnormal atrial-tissue substrate. Various approaches have been developed to interrupt wavelets, including surgical or catheter-mediated atriotomy. Prior to treating the condition, one has to first determine the location of the wavelets. Various techniques have been proposed for making such a determination. None of the proposed techniques, however, provide for measurement of the activity within a pulmonary vein, coronary sinus or other tubular structure about the inner circumference of the structure.
The present invention is directed to a catheter having a mapping assembly and a method for measuring electrical activity within a tubular region of or near the heart, e.g., a pulmonary vein, the coronary sinus, the superior vena cava, or the pulmonary outflow tract. The mapping assembly, which has a generally circular region with a series of spaced-apart electrodes mounted thereon, is positioned within the tubular region so that the electrodes are in contact with an inner generally circumferential surface inside the tubular structure.
In one embodiment, the invention is directed to a mapping catheter comprising an elongated tubular catheter body and a mapping assembly mounted at the distal end of the catheter body. The catheter body has an outer wall, proximal and distal ends, and at least one lumen extending therethrough. The mapping assembly comprises a tubular structure comprising a generally circular main region generally transverse and distal to the catheter body and having an outer circumference and a generally straight distal region distal to the main region. The tubular structure comprises a non-conductive cover over at least the main region of the mapping assembly. A support member having shape-memory is disposed within at least the main region of the mapping assembly. A plurality of electrode pairs, each comprising two ring electrodes, are carried by the generally circular main region of the mapping assembly.
In another embodiment, the invention is directed to a mapping catheter comprising an elongated tubular catheter body and a mapping assembly mounted at the distal end of the catheter body. The catheter body has an outer wall, proximal and distal ends, and at least one lumen extending therethrough. The mapping assembly comprises a tubular structure comprising a generally circular main region generally transverse and distal to the catheter body and having an outer circumference and a generally straight distal region distal to the main region. The tubular structure comprises a non-conductive region over at least the main region of the mapping assembly. A plurality of electrode pairs, each comprising two ring electrodes, are carried by the generally circular main region of the mapping assembly. One ring electrode has a length ranging from about 1 mm to about 1.5 mm, and all of the other ring electrodes each have a length ranging from about 0.4 mm to about 0.75 mm.
In another embodiment, the invention is directed to a mapping catheter comprising an elongated tubular catheter body and a mapping assembly mounted at the distal end of the catheter body. The catheter body has an outer wall, proximal and distal ends, and at least one lumen extending therethrough. The mapping assembly comprises a tubular structure having a generally circular main region generally transverse and distal to the catheter body having an outer circumference. The tubular structure comprises a non-conductive cover over at least the main region of the mapping assembly. A support member having shape-memory is disposed within at least the main region of the mapping assembly. A plurality of electrode pairs are carried by the generally circular main region of the mapping assembly. The catheter further comprises means for deflecting the distal end of the catheter body without altering the shape of the mapping assembly.
In another embodiment, the invention is directed to a mapping catheter comprising an elongated tubular catheter body and a mapping assembly mounted at the distal end of the catheter body. The catheter body has an elongated flexible tubular catheter body having an axis and proximal and distal ends. The mapping assembly has a preformed generally circular curve having an outer surface, is generally transverse to the axis of the catheter body, and carries a plurality of electrode pairs. An electrode lead wire is associated with each electrode. Each electrode lead wire extends through the catheter body and into the mapping assembly. The distal end of each electrode lead wire is electrically connected to its associated electrode. The catheter further includes a puller wire and handle for deflection of the distal end of the catheter body. The puller wire extends through the tubular catheter body. The distal end of the puller wire is fixedly attached to the distal end of the catheter body. The handle is connected to the proximal ends of the catheter body and puller wire for moving the puller wire longitudinally relative to the catheter body, whereby longitudinal movement of the puller wire relative to the catheter body results in deflection of the distal end of the catheter body.
In another embodiment, the invention is directed to a method for mapping electrical activity within a tubular region of or near the heart having a inner circumference. The method comprises inserting the distal end of a catheter as described above into the heart, contacting the outer circumference of the generally circular main region with the inner circumference of the tubular region, and mapping the electrical activity within the tubular region with the electrodes along the generally circular main region. The method is particularly useful for mapping tubular regions such as pulmonary veins, the coronary sinus, the superior vena cava, and the pulmonary outflow tract.